1. Field of the Present Invention
The present invention relates to a diving mask, and more particularly to a frameless diving mask which is covered by two layers made of flexible materials and a method for fabricating the same.
2. Related Art
When people perform underwater activities, they will feel uncomfortable because their eyes are directly in contact with the water. Thus, in order to protect eyes and to see the surrounding environment underwater more clearly, their usually wear diving mask for underwater activities. Categorized by functions, the diving mask can be divided into swimming goggles used in general swimming and diving mask used while scuba diving or skin diving.
Usually, a traditional diving mask is equipped with a large size transparent lens and a flexible facial mask made of silica gel, wherein the large size transparent lens provides user a broad view underwater and the flexible facial mask provides a nice facial coverage and water tightness. Categorized by the structure to assemble the lens to the mask, the diving masks are divided into frameless diving mask and traditional diving mask having a frame.
For example, the diving mask disclosed in U.S. Pat. Nos. 6,405,384 and 6,473,909 are traditional diving masks having a frame. Although a rigid frame provides support to protect the lens, it increases the distance between the lens and the eyes of the user and negatively affects the shape, so that the optical properties and the side view for the eyes may be negatively affected, which may lead to large parallax when use underwater.
In order to improve the optical properties and the field-of-view, a frameless diving mask which has no rigid frame is invented. The mask used to cover the face is directly formed to be combined with the lens of the frameless diving mask, so the distance between the lens and the eyes is shortened, therefore the optical properties is improved and the field-of-view will be better because the obstacle parts of the mask become less. However, because of the difficulty of combining the silica gel to other materials, the frameless diving mask is either opaque (black) or transparent, which is not like the frame diving mask that the trademarks, tags and other stylish designs can be easily printed or added thereon, and thus making the design or shape of the frameless diving mask dull. So, customer's inclination to the goggle may be affected. Later on, a method of enriching the appearance of the frameless diving mask has been proposed, in which two layers of silica gel with different colors are injection-molded twice on the lens to provide color variation. However, there are difficulties that cannot be overcome in the manufacturing process. When the semi-product of the diving mask with the first layer made of silica gel covered thereon is placed in a mold to perform the injection molding of the second layer made of silica gel, the mold is heated to a high temperature and directly contacts the lens and the first layer of silica gel. Therefore, the heat energy is transferred from the high-temperature mold to the lens and the first layer of silica gel. As the lens and the first layer of silica gel have different thermal expansion coefficients, the first layer of silica gel may fall off from the lens during the injection molding of the second layer of silica gel.